2023-01-28 00:38:46

by Srivatsa S. Bhat

Subject: [PATCH] x86/hotplug: Remove incorrect comment about mwait_play_dead()

From: "Srivatsa S. Bhat (VMware)" <[email protected]>

The comment that says mwait_play_dead() returns only on failure is a
bit misleading because mwait_play_dead() could actually return for
valid reasons (such as mwait not being supported by the platform) that
do not indicate a failure of the CPU offline operation. So, remove the
comment.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Srivatsa S. Bhat (VMware) <[email protected]>
---
arch/x86/kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 55cad72715d9..9013bb28255a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1833,7 +1833,7 @@ void native_play_dead(void)
play_dead_common();
tboot_shutdown(TB_SHUTDOWN_WFS);

- mwait_play_dead(); /* Only returns on failure */
+ mwait_play_dead();
if (cpuidle_play_dead())
hlt_play_dead();
}
--
2.25.1

2023-02-14 17:11:05

by Srivatsa S. Bhat

Subject: Re: [PATCH] x86/hotplug: Remove incorrect comment about mwait_play_dead()

Hi,

On 1/27/23 4:37 PM, Srivatsa S. Bhat wrote:
> From: "Srivatsa S. Bhat (VMware)" <[email protected]>
>
> The comment that says mwait_play_dead() returns only on failure is a
> bit misleading because mwait_play_dead() could actually return for
> valid reasons (such as mwait not being supported by the platform) that
> do not indicate a failure of the CPU offline operation. So, remove the
> comment.
>
> Suggested-by: Thomas Gleixner <[email protected]>
> Signed-off-by: Srivatsa S. Bhat (VMware) <[email protected]>


Gentle ping for review. Thank you!

Regards,
Srivatsa

> ---
> arch/x86/kernel/smpboot.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
> index 55cad72715d9..9013bb28255a 100644
> --- a/arch/x86/kernel/smpboot.c
> +++ b/arch/x86/kernel/smpboot.c
> @@ -1833,7 +1833,7 @@ void native_play_dead(void)
> play_dead_common();
> tboot_shutdown(TB_SHUTDOWN_WFS);
>
> - mwait_play_dead(); /* Only returns on failure */
> + mwait_play_dead();
> if (cpuidle_play_dead())
> hlt_play_dead();
> }
>

2023-02-14 22:56:32

by tip-bot2 for Jacob Pan

Subject: [tip: x86/cleanups] x86/hotplug: Remove incorrect comment about mwait_play_dead()

The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID: fcb3a81d221750d2a54b4e3a82b3efbbeab8780c
Gitweb: https://git.kernel.org/tip/fcb3a81d221750d2a54b4e3a82b3efbbeab8780c
Author: Srivatsa S. Bhat (VMware) <[email protected]>
AuthorDate: Fri, 27 Jan 2023 16:37:51 -08:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Tue, 14 Feb 2023 23:44:34 +01:00

x86/hotplug: Remove incorrect comment about mwait_play_dead()

The comment that says mwait_play_dead() returns only on failure is a bit
misleading because mwait_play_dead() could actually return for valid
reasons (such as mwait not being supported by the platform) that do not
indicate a failure of the CPU offline operation. So, remove the comment.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Srivatsa S. Bhat (VMware) <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
arch/x86/kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 55cad72..9013bb2 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1833,7 +1833,7 @@ void native_play_dead(void)
play_dead_common();
tboot_shutdown(TB_SHUTDOWN_WFS);

- mwait_play_dead(); /* Only returns on failure */
+ mwait_play_dead();
if (cpuidle_play_dead())
hlt_play_dead();
}